The purpose of this project is to continue studies which are allowing us to obtain a better understanding of the effects of hypertension on WAIS and neuropsychological test measures with advancing age. Continuation of our ongoing longitudinal studies will allow us to 1) follow subjects, already tested twice, for an additional six years (Time 3 testing); 2) perform Time-2 (follow-up) testing on subjects that were tested for the first time during our present research grant; 3) expand the number of subjects in our overall cross sectional design so that we may obtain the statistical power necessary for examinations of the influence of plasma renin activity, antihypertensive medications, age at initial testing, duration of hypertensive symptoms, and blood pressure levels, on performance. While present numbers of subjects allow evaluations of main effects for these variables, they do not permit us to evaluate these variables in interaction with age and hypertensive status (normotensive versus hypertensive). One universal failing of most all studies in this area is inadequate numbers of subjects, a failure that can only be remedied by persistent and continuous collection of data under controlled conditions. A further objective of continued collection of cross sectional data is the formulation of age/cohorts differing in age by six years (the follow-up time period used in our longitudinal studies). The results of our present longitudinal and cross sectional studies are not in agreement. Cross sectional data indicate more exaggerated performance differences between hypertensives and normotensives for younger than for older subjects while our longitudinal studies indicate just the opposite. However, comparison of cross sectional and longitudinal results are not valid because age differences are considerably larger for our cross sectional sample than for our longitudinal follow-up.